Table 1.
Characteristics and quality/degree of these included paper concerning the association between vitamin D and OSA
| Author, Year | Country | Study design | Male | Ages/n | Sample number | Measurement and type | Quality/Degree | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Control | Mild OSA | Moderate OSA | Severe OSA | Any OSA | |||||||
| Bozkurt 2012 [15] | Altindag,Turkey | CSS | 59.5% | 49.7 ± 9.8 | 47 | 46 | 47 | 50 | 143 | PSG I | 8/A |
| Mete 2013 [10] | Ankara, Turkey | CSS | 50% | 47.1 ± 8.6 | 32 | 50 | 50 | 50 | 150 | PSG I | 6/B |
| *Kheirandish-Gozal 2014 [16] | Chicago,USA | CSS | 52.8% | 6.8 ± 0.8 | 74 | NA | NA | NA | 102 | PSG I | 8/A |
| Erden 2014 [17] | Hatay, Turkey | CSS | 71.1% | 47.4 ± 11.9 | 43 | NA | 23 | 62 | 85 | PSG I | 9/A |
| Liguori 2015 [18] | Rome, Italy | CCS | 67.2% | 60.6 ± 11.7 | 32 | NA | NA | 90 | 90 | PSG I | 8/A |
| Yang 2015 [19] | Shanghai, China | CSS | 75% | 62.5 ± 8.6 | 36 | NA | NA | NA | 36 | PSG I | 7/A |
| Goswami 2016 [20] | Minnesota, USA | CS | 100% | 76.4 ± 5.5 | 1104 | 977 | 470 | 276 | 1723 | PSG I | 8/A |
| Kerley 2016 [9] | Dublin, Ireland | CSS | 68.9% | 54.5(median) | 31 | 22 | 18 | 35 | 75 | PSG I | 8/A |
| Zicari 2016 [21] | Rome, Italy | CSS | 66% | 8.5 ± 2.2 | 70 | NA | NA | NA | 22 | PSG I | 8/A |
| Klobucnikova 2017 [22] | Bratislava, Slovakia | CSS | 73.6% | 56.3 ± 11.9 | 55 | NA | NA | NA | 55 | PSG I | 7/A |
| Toujani 2017 [23] | Tunis, Tunisia | CSS | 54.1% | 52.3 ± 12.7 | 30 | NA | NA | 92 | 92 | PSG I | 8/A |
| Salepci 2017 [24] | Istanbul,Turkey | CSS | 60.2% | 49 ± 12 | 19 | 53 | 38 | 71 | 162 | PSG I | 9/A |
| Archontogeorgis 2017[25] | Alexandroupolis, Greece | CCS | 79.9% | 52.3 ± 13.2 | 30 | NA | NA | NA | 139 | PSG I | 8/A |
| Liguori 2017 [26] | Rome, Italy | CCS | NA | NA | 10 | NA | NA | NA | 39 | PSG I | 8/A |
| Zhang 2017 [27] | Fujian, China | CSS | 91.2% | 45.6 ± 12.2 | 39 | 32 | 21 | 33 | 86 | PSG II | 6/B |
| Zhu 2017 [28] | Shanghai, China | CSS | 51.9% | 46.5 ± 12.8 | 38 | 38 | 46 | 36 | 120 | PSG III | 6/B |
| Liu CY 2017 [29] | Jiangsu,China | CSS | 47.6% | 49.9 ± 5.1 | 20 | NA | NA | NA | 22 | PSG III | 5/B |
| Liu T 2017 [30] | Shandong, China | CSS | 65.8% | 5.9 ± 2.3 | 70 | NA | NA | NA | 47 | PSG II | 8/A |
| Archontogeorgis 2018 [31] | Alexandroupolis, Greece | CCS | 82.2% | 54.8 ± 12.4 | 52 | NA | NA | NA | 55 | PSG I | 7/A |
| Han 2018 [32] | Liaoning, China | CCS | 55% | 43.2 ± 6.8 | 40 | 13 | 12 | 15 | 40 | PSG III | 5/B |
| Ou 2019 [33] | Hunan, China | CSS | 51.1% | 59.7 ± 13.2 | 40 | NA | NA | NA | 40 | PSG II | 4/B |
| Fan 2019 [34] | Guangdong, China | CSS | 88.4% | 27–79 | 8 | 18 | 33 | 53 | 104 | PSG II | 8/A |
| Ragia 2019 [35] | Alexandroupolis, Greece | CCS | 80.1% | 52.2 ± 12.9 | 32 | NA | NA | NA | 144 | PSG I | 7/A |
| Kirac 2019 [36] | Istanbul,Turkey | CSS | 46% | 47.3 ± 9.9 | 50 | NA | NA | NA | 50 | PSG I | 5/B |
| Archontogeorgis 2019 [37] | Alexandroupolis, Greece | CCS | 88% | 50 ± 11.7 | 34 | NA | NA | NA | 58 | PSG I | 8/A |
| Yassa 2019 [11] | Bartin, Turkey | CSS | 81.4% | 46.8 ± 11.3 | 60 | NA | NA | NA | 61 | PSG I | 4/B |
| Bouloukaki 2020 [38] | Crete, Greece | CSS | 74% | 54 ± 15 | 68 | 94 | 150 | 373 | 617 | PSG I | 8/A |
| Siachpazidou 2020 [39] | Larissa,Greece | CS | 63.3% | 53.2 ± 11.6 | 30 | NA | NA | NA | 30 | PSG I | 7/A |
| Ma 2020 [40] | Fujian, China | CSS | 66.2% | 49 ± 14 | 30 | 33 | 31 | 42 | 106 | PSG I | 8/A |
CSS cross sectional study, CCS case–control study, CS cohort studies, OSA obstructive sleep apnea, NA not applicable, PSG polysomnogram;
A: grade A; B: grade B; C: grade C